Demountable and adjustable rolling mill stands which can be installed vertically or horizontally and universal (vertical and horizontal) rolling mill stands are well known.
These rolling mill stands are at times difficult to disassemble for maintenance and to interchange the rollers.
Other aspects regard the gasket support systems of the rollers which are cumbersome or limit the diameter of the respective necks of the rollers.
The universal rolling mill stands, due to their structural complexity, can't easily pretension the force of clamping between the rollers in such a way that up to a certain limit they don't move apart (and beyond this limit they separate) to avoid deformation of the bar in rolling.
A further problem to overcome is that when the rollers separate-they must be able to freely oscillate in order to avoid deformations of the respective support surfaces particularly in the coupling of respective spacers of pretensioning means and in order not to load in an improper way the bearings.
If we want to realize such a structure we are obliged to make it very complex and difficult to be completely demounted.